Some people are much more aware of diacetyl and have a lower tolerance for it. On the other hand, you also get people that can't taste or smell it at all. The "butter topping" that chain movie theaters use for popcorn flavoring is mostly diacetyl, compare that to what you're tasting.

Rice and maize aren't "adjuncts" until they're made into syrup concentrates. When barley, corn or rice syrup is used to make a light lager style, it's macro style brewing on a micro level. That's what I have a problem with.